<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>
        div.box{
           width: 80px;
           height: 80px;
            background-color: aquamarine;
            border-top: 10px solid red;
            border-right: 10px solid yellow;
            border-bottom: 10px solid green;
            border-left: 10px solid purple;
            margin: 100px auto;
        }
    </style>
</head>
<body>
    <div class="box"></div>
</body>
</html>